Fig. 1

The morphology and structure changes of ‘Nong No.8′ pericarp at different development stages. a–c The morphology changes of A. trifoliate pericarp in non-cracking stage (PS) (a), initial cracking stage (PM) (b) and total cracking stage (PL) (c), respectively. d–f Pericarp structure of ‘Nong No.8′ at different development stages using the semi-thin slices method and stained with Safranin O-staining in PS (d), PM (e) and PL (f). g–i Pericarp structure of ‘Nong No.8′ at different development stages using the scanning electron microscope method in PS (g), PM (h) and PL (i). EX. Exocarp; ME. Mesocarp; EN. Endocarp; CU. Cuticle